Presurgical orthopaedic techniques are often used as part of the management of cleft-palate children. Previous investigators have attempted to ameliorate such craniofacial anomalies by some form of intra or extra-orally activated appliances. However because of the erratic cooperation of parents to manually activate such appliances the ever-rising expense of in-hospital care, and the need to streamline the physician's role, an alternative solution would be desirable. The objective of this research is to design, from both conventional and novel materials, a self-activating device for treating unilateral and bilateral cleft-palate children. As a first step, a device is proposed which can be programmed to automatically expand the maxillary segments so that the premaxilla may be retracted to properly align with the rest of the alveolar ridge. Preliminary laboratory investigation will involve a stainless steel appliance in which a coaxial spring arrangement is activated by the "programmed" failure of an irradiated water soluble polymer. By using strain gages and other testing machines, for the first time the magnitude of the forces required to move the bony tissue of the palate will be measured. Appliance fabrication will be developed on the philosophy that each case is unique and requires specific internal hardware which would control the force and displacement requirements. At the same time, however, the external hardware would be universal in design to better accommodate the patient's needs. Clinical assessment will be made first on dogs and later with humans at three different sites. The success of such a project relies on the cooperation of an interdisciplinary team in which engineering plays a key role.